ELECTRON MOMENTUM DENSITIES IN GaxIn1-xAsySb1-y PROBED BY POSITRONS

Abstract

Momentum densities of electron–positron pairs in cubic Ga x In 1-x As y Sb 1-y lattice matched to GaSb and InAs are studied for the first time to the best of our knowledge, with the aim of investigating the disorder and substrate effects on these quantities in the materials for interest. The electron wavefunction is calculated using the pseudopotential band model under the virtual crystal approximation with and without incorporating the effects of compositional variations. The calculations of the positron wavefunction is made in an identical manner, employing the point-core approximation for the ionic potential. It is found that while the electron–positron momentum densities in Ga x In 1-x As y Sb 1-y at x=0.50 are sensitive to the compositional disorder, they are not altered by the change of substrate.